Search for proteomic markers for stunning stress and stress-induced textural tenderization in silver carp (Hypophthalmichthys molitrix) fillets using label-free strategy

A differential proteome analysis using label-free strategy was conducted to elucidate the stunning stress-induced proteome changes and its relationship to textural softening in silver carp (Hypophthalmichthys molitrix) fillets. Compared with the muscle proteome of fillets stunned by percussion, ice/water and gill cut stunning resulted in 43 differentially abundant proteins (DAPs) that were involved in muscle contraction, energy metabolism, antioxidant defense, protein turnover, etc., and gill cut-stunned fillets showed the most significant proteome changes with 28 up- and down-regulated DAPs. In addition, textural softening was more obvious in ice/water- and gill cut-treated fillets and was closely correlated to 21 DAPs including fast muscle troponin T, fragments of myosin, superoxide dismutase [Cu-Zn], ribosomal protein L38, isoform 2 of heat shock cognate 70, two subunits of proteasome, etc., and those DAPs were selected as potential proteomic markers to trace the accelerated textural softening in stunning-stressed fillets.